I R & R tranny when back together I fire up and now have code, that did not have before. P0620 Generator Control Circuit . under hood I had disconnected batteries,and pull dip stick... I"ve had three sets of eyes check for pinched or unattached wires all good. Anyone see a conection between trans install and this code. Customer said he never had it before,and we drove before work and did not have it. after normal start up (no drag).15 seconds later code pops. also battery light does intermittently flashe. scan shows 14.7 v running.

Connectors looked good sprayed them anyway. Customer in a hurry to pick up, said he would take to his motor man. hope he lets me know. Despite Jethro Gibbs Rules I think a coincidence did happen ... I believe alternator went bad.